class_docstr: Swap-in HDF5 File Handler.
code: def _get_global_attrs(self, num_rows, num_cols):
      return {
          "/attr/Equator_Crossing_Longitude": "246.408397",
          "/attr/Equator_Crossing_Time": "20200326T01:37:15.875",
          "/attr/HDF_Version_Id": "HDF5-1.8.16",
          "/attr/Input_L2A_Filename": "H2B_OPER_SCA_L2A_OR_20200326T010839_20200326T025757_07076_dps_250_20.h5",
          "/attr/Instrument_ShorName": "HSCAT-B",
          "/attr/L2A_Inputdata_Version": "10",
          "/attr/L2B_Actual_WVC_Rows": np.int32(num_rows),
          "/attr/L2B_Algorithm_Descriptor": (
              "Wind retrieval processing uses the multiple solution scheme (MSS) for "
              "wind inversion with the NSCAT-4 GMF,and a circular median filter "
              "method (CMF) for ambiguity removal. The ECMWF/NCEP forescate data are "
              "used as background winds in the CMF"
          ),
          "/attr/L2B_Data_Version": "10",
          "/attr/L2B_Expected_WVC_Rows": np.int32(num_rows),
          "/attr/L2B_Processing_Type": "OPER",
          "/attr/L2B_Processor_Name": "hy2_sca_l2b_pro",
          "/attr/L2B_Processor_Version": "01.00",
          "/attr/Long_Name": "HY-2B/SCAT Level 2B Ocean Wind Vectors in 25.0 km Swath Grid",
          "/attr/Orbit_Inclination": np.float32(99.3401),
          "/attr/Orbit_Number": "07076",
          "/attr/Output_L2B_Filename": "H2B_OPER_SCA_L2B_OR_20200326T011107_20200326T025540_07076_dps_250_20_owv.h5",
          "/attr/Platform_LongName": "Haiyang 2B Ocean Observing Satellite",
          "/attr/Platform_ShortName": "HY-2B",
          "/attr/Platform_Type": "spacecraft",
          "/attr/Producer_Agency": "Ministry of Natural Resources of the People's Republic of China",
          "/attr/Producer_Institution": "NSOAS",
          "/attr/Production_Date_Time": "20200326T06:23:10",
          "/attr/Range_Beginning_Time": "20200326T01:11:07",
          "/attr/Range_Ending_Time": "20200326T02:55:40",
          "/attr/Rev_Orbit_Period": "14 days",
          "/attr/Short_Name": "HY-2B SCAT-L2B-25km",
          "/attr/Sigma0_Granularity": "whole pulse",
          "/attr/WVC_Size": "25000m*25000m",
      }
  
imports: import os
  import unittest
  from unittest import mock
  import dask.array
  import numpy
  import pytest
  import xarray
  from satpy.tests.reader_tests.test_hdf5_utils import FakeHDF5FileHandler
label_desc: Use image node_id 7 for calling the FakeHDF5FileHandler2 obj's underlying member method code with example usage: obj._get_global_attrs(num_rows, num_cols) and returns: dict